Heat exchanger

Abstract

A heat exchanger having a plurality of stacked tubes (131) and tanks (110, 120) formed of resin and coupled to the longitudinal ends of the tubes (131), wherein the cooling liquid flowing in a fuel-cell (10) is cooled by being passed through the tubes (131) formed of double layers including a high heat conductivity resin portion (131a) and an insulative resin portion (131b).

Description

TECHNICAL FIELD [0001] This invention relates to a heat exchanger for cooling the fuel-cell of a fuel-cell powered vehicle. BACKGROUND ART [0002] In recent years, a clean fuel-cell powered vehicle, which does not generate any material harmful to the environment, has been under development. The fuel-cell must be cooled by a heat exchanger. During power generation by the fuel-cell, a high voltage is impressed on a cooling medium (such as the cooling water), and therefore the heat exchanger must be electrically insulated. [0003] As a method designed to meet this requirement, the heat exchanger is configured of an insulating material (thermoplastic polymer) (Japanese Unexamined Patent Publication No. 63-311084) or the inner surface of a metal heat exchanger is covered with an insulating material (coated with resin) (Japanese Unexamined Patent Publication No. 2003-181628). [0004] The heat exchanger configured of the insulating material described above, however, has a much lower heat cond...

AI Technical Summary

Benefits of technology

[0006] In view of the problem described above, the object of this invention is to provide a heat exchanger which can be insulated from a fuel-cell without considerably deteriorating the cooling performance.

[0010] Also, the heat transfer can be improved by the high heat conductivity resin portion (131a) of the tubes (131) and, therefore, the cooling performance of the heat exchanger (100) is not considerably deteriorated in spite of a resin being used as a basic material.

[0011] Further, the weight and cost can be reduced by making the tubes (131) of a resin material. Unlike the tube of a metal material, flux used in brazing does not ooze out into the cooling liquid, thereby preventing contamination of the cooling liquid.

[0014] Therefore, the tubes (131) and the tanks (110, 120) can be easily coupled to each other, and so can the fins (132) normally arranged between the tubes (131).

Problems solved by technology

The heat exchanger configured of the insulating material described above, however, has a much lower heat conductivity than the configuration of an aluminum material (about one thousandth of the heat conductivity of aluminum), and therefore the heat transfer performance is deteriorated.

Thus, as the insulation characteristic cannot be maintained, the heat conductivity cannot be easily improved.

Depending on the shape, therefore, some parts may not be covered and it is very difficult to apply the insulating material in a state free of pinholes (defects).

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